TGF-beta to improve neural outcome

ABSTRACT

The invention relates to methods of treating injuries to or diseases of the central nervous system which methods involve increasing the active concentration(s) of transforming growth factor beta 1 (TGF-β1) and/or analogues thereof in the central nervous system of the patient. The present invention also provides pharmaceutical compositions comprising TGF-β1 and/or analogues thereof for administration to a patient prior to, simultaneous with, or following a neural insult, which compositions are useful in minimizing damage to the central nervous system that would otherwise occur following the insult.

FIELD OF THE INVENTION

[0001] This invention relates to methods and pharmaceutical compositionsfor the treatment or prevention of central nervous system (CNS) damageand relates particularly to methods of treatment comprising increasingthe concentration of transforming growth factor beta 1 (TGF-β1) and/oranalogues thereof in the central nervous system of the patient to treatan injury or disease that causes damage to cells of the CNS.

BACKGROUND OF THE INVENTION

[0002] After asphyxial, traumatic, toxic, infectious, degenerative,metabolic, ischemic or hypoxic insults to the central nervous system(CNS) of man a certain degree of neural damage may result. For example,such neural damage can occur in cases of perinatal asphyxia associatedwith intrapartum fetal distress such as following abruption, cordocclusion or associated with intrauterine growth retardation; perinatalasphyxia associated with failure of adequate resuscitation or apnea;severe neural insults associated with near miss drowning, carbonmonoxide inhalation, ammonia of other gaseous intoxication, cardiacarrest, collapse, coma, meningitis, hypoglycemia, or status epilepticus;episodes of cerebral asphyxia associated with coronary bypass surgery;cerebral anoxia or ischemia associated with stroke, hypotensiveepisodes, hypertensive crises; cerebral trauma; or cerebral degenerativediseases such as Alzheimers disease and multiple sclerosis.

[0003] Such neural damage can involve several different cell types ofthe CNS. For example, periventricular leucomalacia, a lesion whichaffects the periventricular oligodendrocytes is generally considered tobe a consequence of hypoxicischemic injury to the developing pretermbrain. Bejar, et al., Am. J. Obstet. Gynecol., 159:357-363 (1988);Sinha, et al., Arch. Dis. Child., 65:1017-1020 (1990); Young, et al.,Ann. Neurol., 12:445-448 (1982). Further cholinergic neuronal cellbodies are absent from most regions of the cortex in primates (Mesulam,et al., Neurosci., 12:669-686 (1984)) and rats (Brownstein, et al., inHandbook of Chemical Neuroanatomy, Classical Transmitters in the CNS,pp. 23-53 (Elsevier, 1984)). Damage to the cerebral cortex by trauma,asphyxia, ischemia, toxins or infection is frequent and may causesensory, motor or cognitive deficits. Glial cells which are non-neuronalcells in the CNS are necessary for normal CNS function. Infarcts are aprinciple component of hypoxic-ischemia induced injury and loss of glialcells is an essential component of infarction. Multiple sclerosis isassociated with loss of myelin and cligodendrocytes, similarlyParkinson's disease is associated with loss of dopaminergic neurons.

[0004] Several growth factors have been reported to be induced aftertransient hypoxic-ischemia in the brain. After postasphyxial seizures,the proto-oncogene c-fos is induced in surviving neurons and in glialcells from infarcted regions. Gunn, et al., Brain Res., S31:105-116(1991). Nerve growth factor (NGF) synthesis is increased after hypoxiaor seizures in the hippocampus and cerebral cortex. Lorez, et al.,Neurosci. Lett., 98:339-344 (1989); Gall, et al., Science, 245:758-761(1989). However, little is known of the role of cytokines in braininjury. Glial cells have been shown to produce a number of cytyokinesincluding interleukin 3 (IL-3) and interleukin 6 (IL-6). Interleukin 1(IL-1) has been reported to be elevated in cerebrospinal fluid afterhead injury in humans. McClain, et al., J. Lab. Clin. Med., 110:48-54(1987).

[0005] Transforming growth factor beta (TGF-β) is another example of acytokine and is a multifunctional polypeptide implicated in theregulation of cellular or tissue response to injury or stress. For ageneral review of TGF-β and its actions, see Sporn, at al., Science,233:532-534 (1986); Spom et al., J. Cell Biol., 105:1039-1045 (1987);Spom, et al., Nature, 3232:217-219 (1988); and Sporn, et al., in PeptideGrowth Factors and Their Receptors I pp.419-472 (Springer-Verlag, 1990).TGF-β is found in various mammalian tissues, such as bone, platelets,and placenta, and methods for purifying the polypeptide from suchnatural sources, as well as for producing it in recombinant cellculture, have been described. See, for example, Assoian, et al., J.Biol. Chem., 258:7155-7160 (1983); Frolik, et al., Proc. Nat. Aced.Sci., 80:3676-3680 (1983); Heimark, et al., Science, 332:1078-1080(1986); Spom, et al., U.S. Pat. No. 5,104,977; Derynck, et al., Nature,316:701-* * * (1985); Derynck, et al., U.S. Pat. No. 4,886,747.

[0006] There are several molecular forms of TGF-β, including those formswhich are commonly referred to as TGF-β1 (Derynck, et al., Nature,316:701-* * * (1985)), TGF-β2 (deMartin, et al., EMBO J., 3673-* * *(1987); Madison, et al., DNA, 7:1-8 (1988)), TGF-β3 (Jakowlew, at al.,Mol. Endocrin., 2:747-755 (1988); Ten Dijke, et al., Proc. Nat. Acad.Sci., 85:4715-4719 (1988); Derynck, et al., EMBO J., 7:3737-* * *(1988)), TGF-β4 (Jakowlew, et al., Mol. Endocrin., 2:1186-1195 (1988),and TGF-β5 (Kondaiah, et al., J. Biol. Chem., 265:1089-* * * (1990).

[0007] It is an object of the invention to provide methods andpharmaceutical compositions for treating or preventing CNS injury ordamage. The invention is based upon the inventors' successful researchinto the role and effects of TGF-β in the CNS.

SUMMARY OF THE INVENTION

[0008] Accordingly, in a first aspect the invention consists in a methodof treating neural damage suffered after a CNS insult characterized inthat it comprises the step of increasing the active concentration(s) ofTGF-β1 and/or analogues of TGF-β1 (such as other molecular forms ofTGF-β) in the CNS of the patient. Preferably, the concentration ofTGF-β1 in the CNS of the patient is increased.

[0009] The term “treat” when used herein refers to the affecting of areduction in the severity of the CNS damage, by reducing infarction, andloss of glial cells, non-cholinergic neuronal cells, or other neuronalcells, suffered after a CNS insult. It encompasses the minimizing ofsuch damage following a CNS insult.

[0010] Preferably, TGF-β1 and/or analogues thereof are administered tothe patient directly. Alternatively, a compound may be administeredwhich upon administration to the patient, increases the activeconcentration of TGF-β1 or naturally occurring analogues of TGF-β1 inthe CNS of the patient. For example, positively regulating bindingproteins of TGF-β1, or naturally occurring analogues thereof may beadministered.

[0011] Preferably, the pharmaceutical compositions described herein areadministered in the period from the time of injury to 100 hours afterthe CNS insult and more preferably 0.5 to 8 hours after the CNS insult.

[0012] In one embodiment of the invention, said TGF-β1 and/or ananalogue or analogues thereof is administered by lateral cerebroventricular injection into the brain of a patient in the inclusiveperiod from the time of the CNS insult to 8 hours thereafter.

[0013] In another embodiment, TGF-β1 and/or an analogue or analoguesthereof is administered through a surgically inserted shunt into thecerebro ventricle of a patient in the inclusive period from the time ofthe CNS insult to 8 hours thereafter.

[0014] In yet another embodiment, TGF-β1 and/or an analogue or analoguesthereof is administered peripherally into a patient for passage into thelateral ventricle of the brain in the inclusive period of from the timeof the CNS insult to 8 hours thereafter. Preferably, it is TGF-β1,itself, that is administered by way of lateral cerebro ventricleinjection or by use of the surgically inserted shunt.

[0015] Preferably the pharmaceutical compositions are administeredaccording to the pattern of injury or time lapsed after a CNS insult.

[0016] Preferably the dosage range administered is from about 0.0001 to100 μg of TGF-β1 or said analogue or said compound that elevates theconcentration thereof per 100 grams of body weight.

[0017] TGF-β1 may be used alone or in conjunction with other therapeuticagents, including other growth factors designed to ameliorate againstloss of CNS cells such as glia and non-cholinergic neurons.

[0018] By “prevent” is meant a reduction in the severity of CNS damagesuffered after a CNS insult and may also include inhibition of thesymptoms of CNS damage.

[0019] In yet a further aspect, the invention relates to the use ofTGF-β1 and/or analogues thereof in the preparation of pharmaceuticalcompositions for treating CNS damage.

[0020] Additionally, the invention comprises the use of a compoundwhich, upon administration to a patient, increases the activeconcentration of TGF-β1 and/or naturally occurring analogues thereof inthe CNS of the patient in the preparation of pharmaceutical compositionsfor treating injury to the CNS.

[0021] The invention also provides pharmaceutical compositions suitablefor treating CNS damage suffered after a CNS insult comprising TGF-β1,and/or analogues thereof optionally provided in a pharmaceuticallyacceptable carrier or diluent.

[0022] The pharmaceutical composition for treating CNS damage may alsocomprise a compound which, upon administration to the patient sufferingCNS damage, increases the active concentration of IGF-1 and/or naturallyoccurring analogues thereof in the CNS of said patient.

BRIEF DESCRIPTION OF DRAWINGS

[0023]FIG. 1 shows composite drawings, illustrating the distribution ofTGF-β1 mRNA, following ischemic hypoxia for Example 1.

[0024]FIG. 2 is a histogram illustrating the neuronal loss for TGF-β1treated and control rats in Example 2.

[0025]FIG. 3 is a histogram illustrating the neuronal loss for TGF-β1treated and control rats in Example 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] The invention relates to a method of treating CNS damage sufferedafter a neural insult. For example, the patient may have sufferedperinatal asphyxia or cerebral asphyxia or ischemia associated with astroke or other non-limiting examples of neural insults having beendescribed earlier herein. In these instances, it is desirable to reduceor eliminate the symptoms of neural damage.

[0027] CNS damage may for example be measured by the degree of permanentneural deficit cognitive function, and/or propensity to seizuredisorders.

[0028] It is desirable that the concentration of TGF-β1 and/or analoguesthereof in the central nervous system and in the brain of the patient inparticular should be increased in order to treat the neural damage.Accordingly, TGF-β1 and/or analogues thereof can be administereddirectly to the patient. By TGF-β1 is meant transforming growth factorbeta-1. By “analogues” (or “biologically active analogues”) of TGF-β1 ismeant compounds which exert a similar biological effect to TGF-β1 andincludes naturally occurring analogues (eg. TGF-β2, TGF-β93, TGF-β4,TGF-β5) or any of the known synthetic analogues of TGF-β1. Thesecompounds can be derived from humans or other animals. TGF-β1 andanalogues can be purified from natural sources or produced byrecombinant DNA techniques.

[0029] Alternatively, compounds can be administered which, uponadministration to the patient, increase the active concentration ofTGF-β1 and/or naturally occurring analogues thereof in the centralnervous system. By “active concentration” is meant the biologicalconcentration of TGF-β1 and/or analogues in the central nervous systemof the patient able to exert an effect on neural damage.

[0030] TGF-β1, its analogues, and compounds which elevate the activeconcentrations thereof can be administered centrally or systematically.Desirably the compositions are administered directly to the CNS of thepatient and in particular to the region where the greatest damage hasoccurred. Accordingly, the compositions are administered directly intothe brain or cerebrospinal fluid by techniques including lateralventricular through a burrhole or anterior fontanelle, lumbar orcisternal puncture or the like. The compositions also are administeredby intravenous, intra-cerebrospinal, intrathecal, or intrasynovialroutes. In addition, they may be administered with other agents orgrowth factors, for example, insulin-like growth factor-1 (IGF-1).

[0031] For the prevention or treatment of CNS injury, the appropriatedosage of TGF-β1 or one of its analogues or a compound capable ofelevating the physiological concentrations of TGF-β1, will depend on thetype of injury to be treated, as defined above, the severity and courseof the injury, whether such TGF-β1 compositions are administered forpreventive or therapeutic purposes, previous therapy, the patient'sclinical history and response to the TGF-β1 compositions, and thediscretion of the attending physician. The TGF-β1 compositions aresuitably administered to the patient at one time or over a series oftreatments.

[0032] The foregoing examples show that the expression of TGF-β1 after aneural insult follows a specified time course and occurs in specifiedareas of the body. Accordingly, the compositions should be administeredaccording to the pattern of CNS damage and time lapsed subsequent to aninsult so as to produce the most desirable results.

[0033] The compositions may for example be administered about 0.5 to 100hours after an insult. Alternatively, the composition may beadministered prior to a potential CNS insult (e.g. prior to cardiacbypass surgery) so as to prevent or reduce the degree of neural damagesuffered after insult.

[0034] A suitable dosage range may for example be between about 0.0001to 100μg of TGF-β1 and/or analogues or compounds that elevate theconcentration thereof per 100 gm of body weight where the composition isadministered centrally.

[0035] The invention also provides pharmaceutical compositions fortreating neural damage suffered after an insult. The pharmaceuticalcompositions comprise TGF-β1 and/or analogues thereof or a compoundwhich elevates the concentration of TGF-β1 in the CNS. TGF-β1, itsanalogues, and compounds that elevate the concentration thereof can bemanufactured by recombinant DNA techniques such as those described inU.S. Pat. No. 4,886,747. Alternatively, such substances an be isolatedfrom natural sources. Optionally, such pharmaceutical compositions areprovided in a pharmaceutically acceptable carrier or diluent that areinherently nontoxic and nontherapeutic. Examples of such carriersinclude ion exchangers, alumina, aluminum stearate, lecithin, serumproteins, such as human serum albumin, buffer substances such asphosphates, glycine, sorbic acid, potassium sorbate, partial glyceridemixtures of saturated vegetable fatty acids, water, salts, orelectrolytes such as protamine sulfate, disodium hydrogen phosphate,polysaccharides such as cellulose or methylcellulose, potassium hydrogenphosphate, sodium chloride, zinc salts, colloidal silica, magnesiumtrisilicate, polyvinyl pyrrolidone, and polyethylene glycol. Suitablediluents include sterile aqueous solutions comprising one or more ofsuch carriers. TGF-β1, is typically formulated at an acidic pH at whichit is biologically active

[0036] The invention is supported by the following experimental data. Inthe studies described in the following Examples, it was found that:

[0037] 1) TGF-β1 mRNA is expressed after a neural insult over a definedtime course in specific regions of injury and TGF-β1 itself can bedetected by immunocytochemistry.

[0038] 2) Alterations in central nervous system levels of TGF-β1 canalter neural outcome resulting as a, consequence of a standardizedneural insult.

[0039] 3) Lower doses of TGF-β1 improve its efficacy in treating neuraldamage. These Examples, however, are offered by way of illustrationonly, and are not intended to limit the invention in any manner. Allpatent and literature references cited throughout the specification areexpressly incorporated.

EXAMPLE 1

[0040] The objective of this study was to study the expression of TGF-β1in the central nervous system after a neural insult.

[0041] Twenty one day old rats were subjected to unilateral carotidligation followed by inhalational asphyxia under defined conditions toproduce either mild or severe neuronal loss on the ligated side.

[0042] Mild or severe neuronal loss was induced in 21 day rates asfollows: The right carotid artery was ligated under light halothaneanesthesia. They were then placed in an incubator at 34° C. and 85%humidity. The inspired gases were replaced by 8% O₂ in nitrogen for 15minutes (mild) or 90 minutes (severe) then returned to air. At varioustimes after hypoxia (1 hour, 5 hours, 3 and 5 days) the animals wereanaesthetized with pentobarbitone (Nembutal), the brains removed andsnap frozen on dry ice for in situ hybridization. For histology, ratswere sacrificed 5 days after hypoxia and then perfused with 0.9% salinefollowed by formaldehyde-acetic acid-methanol (1:1:8).

[0043] At defined times after the asphyxia the rats were sacrificed forhistology. After 90 minutes asphyxia (severe) neuronal loss was assessedby thionine/acid fuchsin stain was widespread within the ligated cortex.There was severe loss of neurons in the middle cerebral arteryterritory, including the lateral cortex, hippocampus, striatum andthalamus. In situ hybridization histochemistry was performed using aTGF-β1 cDNA probe comprising nearly the entire coding sequence ofTGF-β1, provided by Dr. R. Derynck. Hybridization histochemistry wasperformed essentially as described in McCabe, at al., J. Histochem,Cytochem. 34:45-50 (1986) and in Smith, et al., Ann. Neurophathol.,64:319-332 (1984).

[0044] After hybridization, the sections were washed 4 times in 2×SSCplus 10 mM β-mercaptoethanol at room temperature for 10 minutes each, 4times in 2×SSC at room temperature for 10 minutes each, twice in 2×SSCat 50° C. for 10 minutes each.

[0045] Controls were performed using RNAase A (40μg/ml 0.5M NaCl/20mMTris, pH 7.5/1 mM EDTA at 37° C.). RNAase pretreatment almost entirelydepressed the signal Northern blots on each probe revealed theanticipated major band at 2.5 kb.

[0046] The resulting signal for TGF-β1 mRNA as measured by in situhybridization showed an induction of the TGF-β1 mRNA restricted to theareas of neuronal damage. Following mild asphyxia (15 minutes),induction of TGF-β1 mRNA was observed in the ligated brain in layer 3 ofthe cerebral cortex, the dentate gyrus, CA1 and CA 2 regions of thepyramidal layer of the hippocampus.

[0047] Following severe asphyxia (90 minutes), TGF-β1 mRNA wasdetectable by one hour post insult in the hippocampal dentate gyrus, CA1 and CA 2 regions, and choroid plexus. By 5 hours it was detectable inthe cortex and striatum on the ligated side. By 72 hours markedexpression was observed throughout the whole cerebral and puriformcortex, atristum, thalamus and hippocampus of the ligated side but noexpression was observed on the non-ligated side in which no neuronaldeath was observed (FIG. 1).

[0048] The specificity of the induction was demostrated by predominatelyunilateral expression on the ligated side, lesser induction in animalssubjected to a lesser insult and by negative controls using RNAase A.The probe was also used to hybridize a Northern blot of rat liverpoly(A) RNA samples. The bands after hybridization to the TGF-β1 probeare in agreement with the data reported in the literature.

[0049] Immunohistochemistry was performed using anti-h rabbit TGF-β1polyclonal antiserum. Cells staining for TGF-β1 could be identified inthe damaged region of the ligated hemisphere. This staining was seen incells with macrophage-like appearance.

[0050] The data suggests that following an hypoxic ischemic insult,TGF-β1 is induced in macrophages, particularly in the area of damage.

EXAMPLE 2

[0051] The objective of this study was to assess the effect ofadministering TGF-β1 after a neural insult.

[0052] Adult rats (250-350 grams) were used. The experiment involvedtreating the rats with TGF-β1 after a neural insult. These rats had anhypoxic-ischemic insult to one cerebral hemisphere induced in a standardmanner. One carotid artery was ligated and the animal was subjected twohours later to a defined period of inhalational hypoxia. The degree,length of hypoxia, embient temperature and humidity were defined tostandardize the degree of damage. The conditions were inhaled oxygen(6%), 10 minutes of hypoxia at ambient temperature of 31° and 85%humidity. The animals were maintained in an incubator for one hour thenreturned to their standard cages. They were sacrificed five days laterfor histological analysis using stains (acid-fuchsin) specific fornecrotic neurons.

[0053] In such experiments typical neuronal death is restricted to theside of the side of arterial ligation and is primarily in thehippocampus, dentate gyrus and lateral cortex of the ligated hemisphere.

[0054] Unilateral hypoxic-ischemic injury was induced in adult (300±10g)male Wistar rats. The rats underwent unilateral carotid ligation underlight halothane anaesthesia. Following one hour recovery they wereplaced in an incubator at 31° C. and 85±5% humidity for one hour beforeinsult. They were subject to 10 minutes inhalational asphyxia (FiO26.0%) and maintained in the incubator for one hour after asphyxia. Twohours after the termination of the inhalational is, a singlestereotaxically controlled lateral carebroventricular injection ofeither 0.05 μg recombinant TGF-β1 or artificial cerebrospinal fluid(CSF) was given.

[0055] Recombinant TGF-β1 or diluent was prepared and administered toweight-matched pairs as follows: Two hours after asphyxia the rats weregiven a light halothane anaesthetic, and a single ICV injection ofeither 20 μl of CSF (n-6) or 20 μl of CSF plus 0.05 μg TGF-β1 (n-6) wasgiven. Recombinant TGF-β1 (Genentech, Inc., South San Francisco, Calif.94080 USA) was dissolved in the CSF diluent at 2.5 μg/ml. This solutionwas diluted 9 times with 0.15 M PBS (phosphate buffered saline) giving apH of 7.0.

[0056] The animals were then maintained for 120 hours, anaesthetized andthe brains fixed in situ with formaldehyde-acetic acid-methanol (1:1:8)for histological assessment.

[0057] Surviving and dead neurons were discriminate with the use of anthionin/acid fuschin staining technique. Williams, at al., Ped. Res.,27:561-565 (1990); Brown, et al., J. Neurol. Sci., 16:59-84 (1971).

[0058] The degree of neural damage suffered was quantified by measuringthe neuronal loss score. The neuronal loss scores are the average fromthe susceptible regions of the hippocampus and cerebral cortex (100%equals total loss of neurons, 0% equals 0 loss).

[0059] The percentage of dead neurons was estimated by two independentobservers, one of whom was blinded to the experiment. The correlationbetween scores obtained by the two observers was r-0.92 p,0.0001. Theeffect of treatment was evaluated with MANOVA followed by pair wisecomparisons of each region using Fisher's least-significant-differenceprocedure.

[0060] The results are shown in FIG. 2. TGF-β1 therapy reduced theextent of neuronal death in the ligated hemisphere compared to theCSF-treated controls (p<0.01). A single central injection of TGF-β1following an asphyxial insult in the adult rat was associated with amarked improvement in outcome as assessed histologically (See Table 1).TABLE 1 Effect of TGF-β1 treatment on percent neuronal loss followinghypoxic-ischemic injury (6 groups; mean ± sem). % Neuronal loss upontreatment with Region CSF (control) TGF-β1 (0.05 μg) Hippocampal CA1-298.4 ± 4 7.6 ± 5 Hippocampal CA3 100.0  4.0 ± 4 Hippocampal CA4 100.000.0 Dentate gyrus 97.2 ± 3 0.0 Pyriform cortex 93.2 ± 7 0.0 Lateralcortex 98.0 ± 2 5.0 ± 5

EXAMPLE 3

[0061] The objective of this study was to confirm the observations ofExample 2 and establish the most effective dosage range.

[0062] The experiment was the same to that of Example 2 except that twofurther groups were treated with higher doses of TGF-β1.

[0063] Hypoxic-ischemic insult was induced in rats a discussed forExample 2. Rats (n-6 for each treatment) were administered either CSF,CSF+0.05 μg TGF-β1, CSF+0.5 μg TGF-β1 or CSF +5 μg TGF-β1 two hoursafter the inhalational insult. Rats (n-1) from each treatment weretreated simultaneously. The same techniques for measuring the degree ofinsult at those discussed for Example 2 where employed.

[0064] The results are shown in FIG. 3. As can be seen, 5 μg TGF-β1 hadno significant effect on neuronal loss. On the other hand, 0.5 μg TGF-β1reduced (p<0.05) neuronal loss in the cerebral cortex but 0.05 μg TGF-β1was significantly (p <0.05) more effective. Similar effects were seen inother neuronal areas. Further experiments have shown that dosages in therange of about 0.01 μg to 0.05 μg are most effective.

DISCUSSION

[0065] The results of the experiments described above were statisticallyhighly significant. In Examples 2 and 3, where TGF-β1 was givenpost-asphyxia, TGF-β1 therapy at doses less than 0.5 μg/rat or lowermarkedly improved outcome compared to CSF treated controls. We thereforeconclude that therapeutic elevation of TGF-β1 in the cerebral spinalfluid either directly or indirectly after an insult is advantageous tooutcome. The results in Example 3 further show that the greatestefficacy is seen at low doses of TGF-β1.

[0066] The present invention, therefore, recognizes the role of anadministration of TGF-β1 and/or other compounds of similar effect into apatient prior to, simultaneous with, or following a CNS insult with theconsequential result that CNS damage is minimized by preventing theotherwise consequential damage that otherwise would occur following theinjury. The invention provides methods and pharmaceutical compositionsfor treating or for preventing neural damage. Neural damage may beassociated with asphyxia, hypoxia, toxins, ischemia or trauma. Althoughit will be appreciated that the main application of the invention is tohumans, the usefulness of the invention is not limited thereto andtreatment of non-human animals (especially mammals) is also within thescope of the invention.

What is claimed is:
 1. A method of treating central nervous systeminjury in a mammal, comprising administering to the central nervoussystem of said mammal an effective amount of TGF-β1 or a biologicallyactive analogue of TGF-β1.
 2. A method of claim 1 wherein the centralnervous system injury is hypoxic injury.
 3. A method of claim 1 whereinthe central nervous system injury is ischemic injury.
 4. A method ofclaim 1 wherein the central nervous system injury is traumatic injury.5. A method of claim 1 wherein the central nervous system injury affectsnon-cholinergic neuronal cells.
 6. A method of claim 1 wherein thecentral nervous system injury affects glial cells.
 7. A method of claim1 wherein the central nervous system injury is a consequence ofParkinson's disease.
 8. A method of claim 1 wherein the central nervoussystem injury is a consequence of multiple sclerosis.
 9. A method ofclaim 1 wherein the central nervous system injury is a consequence of ademyelinating disorder.
 10. A method of claim 1 wherein the TGF-β1 orbiologically active analogue of TGF-β1 is administered in the periodfrom the time of the central nervous system injury to 100 hours afterthe injury.
 11. A method of claim 1 wherein the TGF-β1 or biologicallyactive analogue of TGF-β1 is administered at least once in the periodfrom the time of the central nervous system injury to about 8 hourssubsequently.
 12. A method of claim 1 wherein the TGF-β1 or biologicallyactive analogue of TGF-β1 is administered to the mammal in an amountfrom about 0.0001 to 100 μg of TGF-β1 per 100 gm of body weight of themammal.
 13. A method of claim 1 wherein the biologically active analogueof TGF-β1 is selected from the group consisting of TGF-β2, TGF-β1,2,TGF-β3, TGF-β2,3, TGF-4, and TGF-β5.
 14. A method of claim 1 wherein theTGF-β1 or biologically active analogue of IGF-1 is administered to themammal through a surgically inserted shunt into the cerebro ventricle ofthe mammal.
 15. A method of claim 1 wherein the TGF-β1 or biologicallyactive analogue of TGF-β1 is administered peripherally into the mammalfor passage into the lateral ventricle of the brain.